bcachefs: Add an "ignore unknown" option to bch2_parse_mount_opts()

To be used by the mount helper in userspace, where we still have options
to be parsed by other layers.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

Author: Kent Overstreet

fs/bcachefs/fs.c

@@ -2179,7 +2179,7 @@ static int bch2_fs_get_tree(struct fs_context *fc)
 
 	/* Some options can't be parsed until after the fs is started: */
 	opts = bch2_opts_empty();
-	ret = bch2_parse_mount_opts(c, &opts, NULL, opts_parse->parse_later.buf);
+	ret = bch2_parse_mount_opts(c, &opts, NULL, opts_parse->parse_later.buf, false);
 	if (ret)
 		goto err_stop_fs;
 
@@ -2334,6 +2334,8 @@ static int bch2_fs_parse_param(struct fs_context *fc,
 	int ret = bch2_parse_one_mount_opt(c, &opts->opts,
 					   &opts->parse_later, param->key,
 					   param->string);
+	if (ret)
+		pr_err("Error parsing option %s: %s", param->key, bch2_err_str(ret));
 
 	return bch2_err_class(ret);
 }

fs/bcachefs/fsck.c

@@ -3021,7 +3021,7 @@ long bch2_ioctl_fsck_offline(struct bch_ioctl_fsck_offline __user *user_arg)
 	if (arg.opts) {
 		char *optstr = strndup_user((char __user *)(unsigned long) arg.opts, 1 << 16);
 		ret =   PTR_ERR_OR_ZERO(optstr) ?:
-			bch2_parse_mount_opts(NULL, &thr->opts, NULL, optstr);
+			bch2_parse_mount_opts(NULL, &thr->opts, NULL, optstr, false);
 		if (!IS_ERR(optstr))
 			kfree(optstr);
 
@@ -3129,7 +3129,7 @@ long bch2_ioctl_fsck_online(struct bch_fs *c, struct bch_ioctl_fsck_online arg)
 		char *optstr = strndup_user((char __user *)(unsigned long) arg.opts, 1 << 16);
 
 		ret =   PTR_ERR_OR_ZERO(optstr) ?:
-			bch2_parse_mount_opts(c, &thr->opts, NULL, optstr);
+			bch2_parse_mount_opts(c, &thr->opts, NULL, optstr, false);
 		if (!IS_ERR(optstr))
 			kfree(optstr);
 

fs/bcachefs/opts.c

@@ -549,14 +549,15 @@ int bch2_parse_one_mount_opt(struct bch_fs *c, struct bch_opts *opts,
 		goto bad_opt;
 
 	ret = bch2_opt_parse(c, &bch2_opt_table[id], val, &v, &err);
-	if (ret == -BCH_ERR_option_needs_open_fs && parse_later) {
-		prt_printf(parse_later, "%s=%s,", name, val);
-		if (parse_later->allocation_failure) {
-			ret = -ENOMEM;
-			goto out;
+	if (ret == -BCH_ERR_option_needs_open_fs) {
+		ret = 0;
+
+		if (parse_later) {
+			prt_printf(parse_later, "%s=%s,", name, val);
+			if (parse_later->allocation_failure)
+				ret = -ENOMEM;
 		}
 
-		ret = 0;
 		goto out;
 	}
 
@@ -567,28 +568,24 @@ int bch2_parse_one_mount_opt(struct bch_fs *c, struct bch_opts *opts,
 		bch2_opt_set_by_id(opts, id, v);
 
 	ret = 0;
-	goto out;
-
+out:
+	printbuf_exit(&err);
+	return ret;
 bad_opt:
-	pr_err("Bad mount option %s", name);
 	ret = -BCH_ERR_option_name;
 	goto out;
-
 bad_val:
-	pr_err("Invalid mount option %s", err.buf);
 	ret = -BCH_ERR_option_value;
-
-out:
-	printbuf_exit(&err);
-	return ret;
+	goto out;
 }
 
 int bch2_parse_mount_opts(struct bch_fs *c, struct bch_opts *opts,
-			  struct printbuf *parse_later, char *options)
+			  struct printbuf *parse_later, char *options,
+			  bool ignore_unknown)
 {
 	char *copied_opts, *copied_opts_start;
 	char *opt, *name, *val;
-	int ret;
+	int ret = 0;
 
 	if (!options)
 		return 0;
@@ -613,14 +610,14 @@ int bch2_parse_mount_opts(struct bch_fs *c, struct bch_opts *opts,
 		val	= opt;
 
 		ret = bch2_parse_one_mount_opt(c, opts, parse_later, name, val);
-		if (ret < 0)
-			goto out;
+		if (ret == -BCH_ERR_option_name && ignore_unknown)
+			ret = 0;
+		if (ret) {
+			pr_err("Error parsing option %s: %s", name, bch2_err_str(ret));
+			break;
+		}
 	}
 
-	ret = 0;
-	goto out;
-
-out:
 	kfree(copied_opts_start);
 	return ret;
 }

fs/bcachefs/opts.h

@@ -636,7 +636,7 @@ int bch2_opts_check_may_set(struct bch_fs *);
 int bch2_parse_one_mount_opt(struct bch_fs *, struct bch_opts *,
 			     struct printbuf *, const char *, const char *);
 int bch2_parse_mount_opts(struct bch_fs *, struct bch_opts *, struct printbuf *,
-			  char *);
+			  char *, bool);
 
 /* inode opts: */